|Reproductive variability in North Sea plaice, sole, and cod|
Rijnsdorp, A.D.; Daan, N.; Van Beek, F.A.; Heessen, H.J.L. (1991). Reproductive variability in North Sea plaice, sole, and cod. J. Cons. - Cons. Int. Explor. Mer 47(3): 352-375
In: Journal du Conseil - Conseil International pour l'Exploration de la Mer. Conseil International pour l'Exploration de la Mer: Copenhague. ISSN 0020-6466, more
Annual variations; Density dependence; Fecundity; Growth; Marine fisheries; Potential yield; Sexual maturity; Gadus morhua Linnaeus, 1758 [WoRMS]; Pleuronectes platessa Linnaeus, 1758 [WoRMS]; Solea solea (Linnaeus, 1758) [WoRMS]; Marine
|Authors|| || Top |
- Rijnsdorp, A.D., more
- Daan, N.
- Van Beek, F.A.
- Heessen, H.J.L., more
The between-year variability in reproductive potential of the stocks of North Sea plaice, sole, and cod is investigated using time series of growth, maturation, and fecundity. Special attention is given to possible density-dependent effects. The growth rate of both plaice and sole increased in the 1960s. Evidence of density-dependent effects was observed only in the somatic growth of juvenile plaice and in the condition factor of sole. However, these results can also be explained by concurrent time trends. The age, but not length, of plaice at first maturity was correlated with juvenile growth. Fecundity of cod and ovary weight of sole were positively correlated with spawning biomass, whereas a weak positive correlation between fecundity and growth was observed in plaice. In general, there was very little evidence that variability in the reproductive parameters of these species is related to population density. The data suggest that conditions for growth vary substantially between years, but are independent of stock size at the present level of exploitation.